1. Field of Invention
The present invention relates to an agricultural grinder mixer and more particularly to the operation of the hammer mill and the removal of ground fines of milled material.
2. Description of Prior Art
Grinder mixers known to Applicants employ a large mixing tank mounted on a mobile frame. Forwardly of the mixing tank a hammer mill is fixed to the frame for receiving grain of various descriptions which is ground and cut to small size and then transferred to the mixing tank by a transfer auger. Such grinder mixers are described in greater detail in prior U.S. Pat. Nos. 3,780,993 and 3,997,146.
The hammer mill includes an exhaust fan arrangement for removing dust and other airborne particles that are produced during the milling process. The particles after separation from the air are allowed to fall into the transfer auger or are otherwise transmitted to the mixing tank.
The milled material falls onto the bottom of the mill into a transfer auger mounted therein where the material is transferred to the mixer. The duct for removal of airborne material is connected to the exhaust fan and is arranged near the bottom of the mill at or near the end of the transfer auger.
It has been found with this conventional arrangement that blockages are mainly caused by pieces of straw lodging in the mouth of the duct around which duct other particles accumulate eventually resulting in a blockage of the duct. This blockage results in reduced air flow in the duct and to the cyclone thereby resulting in increased discharge of fine material from the cyclone exhaust. This leads to pollution of the atmosphere around the machine leading to discomfort of the operators.
The blockage can only be cleared by stopping the machine and manually clearing the debris from the duct. Such blockages occur frequently in some conditions and result in considerable down time of the equipment.